Buying and using crypto currency

[Frobwer]

I am wondering how would I go about buying crypto currency (ex. Bitcoin) and then using it to buy let’s say a pizza. Say I bought 20 dollars worth of bitcoin to start with and the pizza costed 10 dollars. How would I report that on my taxes or what would I need to record in order to report that. 

[sp55]

Buy a real crypto that can't be traced:)   🤣